Steam boiler



July 3, 1928. 1,675,592

0. H. HARTMANN ET AL.

STEAM BOILER Filed June 15, 1925 2 Sheets-She et 1 I w/nvzss INVENTORS 7 arm 1/. Hum/mum [nu/m0 BLE/T/YE/F By W A TTOR/VEYS Patented July 3, 1928.

UNITED STATES PATENT OFFICE.

OTTO HERMAFI'N HARTMANN AND EDUARD BLEITNER, OF KASSEL-WILHELMSHOHE, GERMANY, ASSIGNOR TO SCHMIDTSCHE HEISSDAMPF-GESELLSCHAFT M. B. H., 015 KASSEL-WILHELMSHOHE, GERMANY, A CORPORATION OF GERMANY.

STEAM BOILER.

Application filed June 15, 1923, Serial No. 645,500, and in Germany June 28, 1922.

Our invention relates to steam boilers, and has for its object to safeguard the water and steam containers of such boilers against the injurious effects of uneven heating.

. These containers are usually heated from one side, and this impairs the durability of the material from which the boiler is made. The heating with furnace gases produces local accumulations of heat in the boiler walls, 1 and this in time causes the material to weaken and also affects injuriously the riveted joints of the walls of said containers. This is the case especially when the boilers are made with upright tubes and are intended for high steam pressures. In boilers of this type, the heat generally is applied particularly to those portions of the containers which have been weakened by their connection with the said tubes, and where to compensate for such weakening the container walls are made of increased thickness. It has been proposed to protect those portions of the container walls which are exposed to the furnace gases by means of asbestos plates or of partitions. This, however, decreases the efl'ective heating surface. Furthermore partitions are liable to become incandescent under strong heating and in that case they will be destroyed in time.

The above-mentioned drawbacks are avoided by our present invention. For this purpose we arrange in advance of the water and steam containers, that is to say, on the side of those containers which faces the source of heat, a wall made of hollow bodies,

for instance, tubes containing a cooling medium. These tubes may be filled, for instance, with water, or a cooling medium such as steam or air may circulate through case the water them. In the former passed through the tubes may be the boiler feed water, the apparatus then constituting at the'same time a feed water heater or the tubes containing water may be used for the generation of steam. In the latter case the tubes may. act as a superheate'r structure for the steam or as a preheater for the air employed for supporting combustion in the furnace. The cooled wall formed in this manner resists the destructive effect of the eat and forms a reliable protection for the container wall against the furnace gases.

At the same time the heat absorbed by this boiler.

protective wall is utilized in an advantageous manner.

In the accompanying drawing, two forms of this invention have been illustrated as examples in connection with upright tube boilers. Fig. l is a cross section of a portion of a boiler embodying our invention: Fig. 2 is a partial longitudinal section and Fig. 3 is a partial plan View; Figs. 4, 5 and 6 show a second form of this invention and corresponds to Figs. 1, 2 and 3, respectively.

In the example of our invention illustrated by Figs. 1, 2 and 3, a indicates a steam and water collector forming part of the Tubes 6 extend downwardly from the lower portion of said collector or container in the manner well known in this type of boiler. According to our invention a protective wall is placed at a suitable distance below the said container a, this protective wall consisting of tubes 0 extending lengthwise of the container and located between the adjacent upright tubes 6. These tubes 0 are provided with lateral flanges or ribs (Z recessed as shown in Fig. 3 to fit around the adjacent upright tubes 1). The flanges d of adjoining tubes 0 are in contact with each other; they may simply abut against each other as indicated in Figs. 1 and 3 or, if desired, such flanges may over- .lap. We thus form a continuous wall consisting of the tubes 0 and their flanges d which protects the container wand particularly the lower portion thereof from the injurious excessive heating action of the furnace gases. The wall constituted by these tubes 0 is supported at its ends upon the boiler setting. in any suitable manner. A cooling medium such as water, air or steam, may be circulated through the pipes c: if this cooling medium is water, it may be either the feed water on its way to the boiler, or water to be converted into steam within the tubes 0; if air is circulated through the tubes 0 such air may be employed to support combustion in the boiler furnace; if steam is circulated through the tubes 0 such steam may be superheated by the action of the furnace gases, that is to say, in this casethe tubes 0 would constitute a superheater for the steam.

In the second example of our lnvention illustrated by Figs. 4, 5 and 6, the protective neath the container o appropriate construction.

wall located under the container a is formed by two sets of tubes e and f of which the tubes f are arranged lengthwiseof the container ax'is while the tubes e are arranged at right angles to the tubes f. The tubes 6 are shown curved corresponding to the relative arrangement of the several tubes f while this arrangement is preferred, we do not desire to restrict ourselves thereto. In this form of our invention we generally use the upper transverse tubes e for the circulation of steam sothat they will form a steam superheater, while the lower set of tubes is generally employed as a feed water heater. It will be seen that the two sets of tubese, f, arranged crosswise of each other will form a practically continuous protective wall be- Fig. 6 shows that the only openings in this protecting wall will be very small and these small openings will, in the operation of the boiler, very soon be stopped by cinders, ashes and the like coming from the furnace so that the wall will then be absolutely imperforate. If it is not desired to rely on the closing of these openings by the operation of the furnace, we might apply a filling of refractory material to close the small openings. The water tubes f and the superheater tubes 6, are supported on the boiler setting in such a way that after lifting these tubes from their supports, such tubes may be pulled out from between the upright tubes b. The superheater tubes 0 may be constructed in such a manner (see Figs. 5 and 6) as to have two runs side by side between adjoining sets of upright tubes 6 and the two runs are connected at their ends by elbows or by chambered heads of When the sets of tubes f are so close to each other that there is no room for placing two tubes'e side by side between them, the two tubes e or the tWo runs could be located one above the other and we might also employ more than two runs of such tubes.

Various changes in the specific form shown and described may be made within the scope 'of the claimswithout departing from the spirit of our invention.

Ne claim:

1. In a steam boiler, a water container,

f spaced water tubes extending'from said cone taincr and communication therewith, spaced, protective tubes extending between and" transversely of said water tubes,'and means for closing the gaps between said tubes.

2. In a steam boiler, an elongated water container, spaced water tubes extending from said container transversely thereof and communicating therewith, protective tubes extending lengthwise of the container between said water tubes, and means for closing the gaps between said tubes to form a protective wall.

3. In a steam boiler, a steam and water container, spaced water tubes communicating with said container and extending therefrom, and a protective wall for maintaining said container out of direct contact with the heating gases consisting of tubes arranged lengthwise of the container between said water tubes and provided with flanges extending into mutual contact.

In testimony whereof we have hereunto set our hands.

OTTO HERMANN HARTMANN. [L. s.] EDUARD BLEITNER. [L.s.] 

